<template>
	<div class="wrapper">

		<!-- header部分 -->
		<header>
			<div class="go-back"><i class="fa fa-reply" @click="goback"></i></div>
			<p>商家信息</p>
		</header>

		<!-- 商家logo部分 -->
		<div class="business-logo">
			<img :src="business.businessImg">
			<!--动态绑定图片-->
		</div>

		<!-- 商家信息部分 -->
		<div class="business-info">
			<h1>{{business.businessName}}</h1>
			<p>&#165;{{business.starPrice}}起送 &#165;{{business.deliveryPrice}}配送</p>
			<p>{{business.businessExplain}}</p>
		</div>

		<!-- 食品列表部分 -->
		<ul class="food">
			<li v-for="(item,index) in foodArr">
				<!--遍历附带索引便于之后选定食品-->
				<div class="food-left">
					<img :src="item.foodImg">
					<div class="food-left-info">
						<h3>{{item.foodName}}</h3>
						<p>{{item.foodExplain}}</p>
						<p>&#165;{{item.foodPrice}}</p>
					</div>
				</div>
				<div class="food-right">
					<div>
						<i class="fa fa-minus-circle" @click="minus(index)" v-show="item.quantity!=0"></i>
						<!--v-show指令通过改变元素的css属性来决定元素是显示还是隐藏-->
					</div>
					<p><span v-show="item.quantity!=0">{{item.quantity}}</span></p>
					<!--内连元素-->
					<div>
						<i class="fa fa-plus-circle" @click="add(index)"></i>
					</div>
				</div>
			</li>
		</ul>
		
		<div class="whiteblock"></div>
		
		<!-- 购物车部分 -->
		<div class="cart">
			<ul class="cart-detailed" v-show="this.business.button==true&&this.cartArr!=null">
				<li v-for="item in cartArr">
					<div class="cart-detailed-left">
						<!--<img :src="item.food.foodImg">-->
						<p>{{item.food.foodName}} x {{item.quantity}}</p>
					</div>
					<p>&#165;{{item.food.foodPrice*item.quantity.toFixed(2)}}</p>
				</li>
			</ul>
			<div class="cart-bottom">
				<div class="cart-left">
					<div class="cart-left-icon" :style="totalQuantity==0?'background-color:#505051;':'background-color:#3190E8;'">
						<i class="fa fa-shopping-cart" @click="topressbutton"></i>
						<div class="cart-left-icon-quantity" v-show="totalQuantity!=0">{{totalQuantity}}</div>
					</div>
					<div class="cart-left-info">
						<p>&#165;{{totalPrice}}</p>
						<p>另需配送费{{business.deliveryPrice}}元</p>
					</div>
				</div>
				<div class="cart-right">
					<!-- 不够起送费 -->
					<div class="cart-right-item" v-show="totalSettle<business.starPrice" style="background-color: #535356;cursor: default;">
						&#165;{{business.starPrice}}起送
					</div>
					<!-- 达到起送费 -->
					<div class="cart-right-item" @click="toOrder" v-show="totalSettle>=business.starPrice">
						去结算
					</div>
				</div>
			</div>
		</div>

	</div>
</template>

<script>
	export default {
		name: 'BusinessInfo',
		data() {
			return {
				businessId: this.$route.query.businessId, //从BusinessList组件传入id值
				business: {}, //返回一个business对象
				foodArr: [], //食品数组
				user: {}, //添加用户对象
				cartArr: []
			}
		},
		created() {
			this.user = this.$getSessionStorage('user'); //从sessionStorage中获取user对象

			//根据businessId查询商家信息
			this.$axios.post('BusinessController/getBusinessById', this.$qs.stringify({
				businessId: this.businessId
			})).then(response => {
				this.business = response.data;
			}).catch(error => {
				console.error(error);
			});

			//根据businessId查询所属食品信息
			this.$axios.post('FoodController/listFoodByBusinessId', this.$qs.stringify({
				businessId: this.businessId
			})).then(response => {
				this.foodArr = response.data;
				for (let i = 0; i < this.foodArr.length; i++) { //为每个食品添加数量属性，初始赋为0
					this.foodArr[i].quantity = 0;
				}
				//如果已登录，那么需要去查询购物车中是否已经选购了某个食品
				//该操作是必要的，否则刷新页面前端数据丢失，与后端数据不一致产生问题
				if (this.user != null) {
					this.listCart2();
				}
			}).catch(error => {
				console.error(error);
			});
		},
		methods: {
			listCart() {
				this.$axios.post('CartController/listCart', this.$qs.stringify({
					businessId: this.businessId,
					userId: this.user.userId
				})).then(response => {
					this.cartArr = response.data;
					this.cartArr.sort();
				}).catch(error => {
					console.error(error);
				});
			},
			listCart2() {
				this.$axios.post('CartController/listCart', this.$qs.stringify({
					businessId: this.businessId,
					userId: this.user.userId
				})).then(response => {
					let cartArr = response.data;
					//遍历所有食品列表
					for (let foodItem of this.foodArr) {
						foodItem.quantity = 0;
						for (let cartItem of cartArr) {
							if (cartItem.foodId == foodItem.foodId) {
								foodItem.quantity = cartItem.quantity;
							}
						}
					}
					this.foodArr.sort();
				}).catch(error => {
					console.error(error);
				});
			},
			add(index) { //食品数量加1，传过来index指定某个食品
				//首先做登录验证（很重要）
				if (this.user == null) { //根据user对象是否为空判断是否登录
					this.$router.push({
						path: '/login'
					}); //如果未登录强制路由到登录组件
					return; //接着之后直接退出
				}
				if (this.foodArr[index].quantity == 0) { //如果开始数量为0做insert
					this.savaCart(index);
				} else { //否则如果开始数量不为0做update
					this.updateCart(index, 1);
				}
			},
			minus(index) { //食品数量减1
				if (this.user == null) {
					this.$router.push({
						path: '/login'
					});
					return;
				}
				if (this.foodArr[index].quantity > 1) { //如果开始数量大于1个做update
					this.updateCart(index, -1);
				} else { //否则如果开始数量为1个做remove
					this.removeCart(index);
				}
			},
			savaCart(index) { //向购物车表中添加一条记录
				this.$axios.post('CartController/saveCart', this.$qs.stringify({
					businessId: this.businessId,
					userId: this.user.userId,
					foodId: this.foodArr[index].foodId
				})).then(response => {
					if (response.data == 1) { //当后端响应成功才更新前端数据
						this.foodArr[index].quantity = 1; //此食品数量要更新为1
						this.foodArr.sort(); //调用sort监听方法目标在于让vue监听到数据的变化而非排序
						this.listCart();
					} else {
						alert('向购物车中添加食品失败！');
					}
				}).catch(error => {
					console.error(error);
				});
			},
			updateCart(index, num) {
				this.$axios.post('CartController/updateCart', this.$qs.stringify({
					businessId: this.businessId,
					userId: this.user.userId,
					foodId: this.foodArr[index].foodId,
					quantity: this.foodArr[index].quantity + num
				})).then(response => {
					if (response.data == 1) {
						this.foodArr[index].quantity += num; //此食品数量要更新为1或-1；
						this.foodArr.sort();
						this.listCart();
					} else {
						alert('向购物车中更新食品失败！');
					}
				}).catch(error => {
					console.error(error);
				});
			},
			removeCart(index) {
				this.$axios.post('CartController/removeCart', this.$qs.stringify({
					businessId: this.businessId,
					userId: this.user.userId,
					foodId: this.foodArr[index].foodId
				})).then(response => {
					if (response.data == 1) {
						this.foodArr[index].quantity = 0;//此食品数量要更新为0；视图的减号和数量要消失
						this.foodArr.sort();
						this.listCart();
					} else {
						alert('从购物车中删除食品失败！');
					}
				}).catch(error => {
					console.error(error);
				});
			},
			toOrder() {
				this.$router.push({
					path: '/orders',
					query: {
						businessId: this.business.businessId
					}
				});
			},
			topressbutton() {
				this.business.button = !this.business.button;
				this.listCart();
			}
		},
		computed: {
			//食品总价格
			totalPrice() {
				let total = 0;
				for (let item of this.foodArr) {
					total += item.foodPrice * item.quantity;
				}
				return total;
			},
			//食品总数量
			totalQuantity() {
				let quantity = 0;
				for (let item of this.foodArr) {
					quantity += item.quantity;
				}
				return quantity;
			},
			//结算总价格
			totalSettle() {
				return this.totalPrice + this.business.deliveryPrice;
			},
			goback() {
				this.$router.go(-1);
			}
		}
	}
</script>

<style scoped>
	/****************** 总容器 ******************/
	.wrapper {
		width: 100%;
		height: 100%;
	}
	
	.wrapper .whiteblock {
		width: 100%;
		height: 2vw;
	}
	/****************** header部分 ******************/
	.wrapper header {
		width: 100%;
		height: 12vw;
		background-color: #0097FF;
		color: #fff;
		font-size: 4.8vw;

		position: fixed;
		left: 0;
		top: 0;
		z-index: 1000;

		display: flex;
		/*justify-content: center;*/
		align-items: center;
	}

	.wrapper header .go-back {
		padding: 0 32vw 0 2vw;
	}

	/****************** 商家logo部分 ******************/
	.wrapper .business-logo {
		width: 100%;
		height: 35vw;
		/*使用上外边距避开header部分*/
		margin-top: 12vw;

		display: flex;
		justify-content: center;
		align-items: center;
	}

	.wrapper .business-logo img {
		width: 40vw;
		height: 30vw;
		border-radius: 5px;
	}

	/****************** 商家信息部分 ******************/
	.wrapper .business-info {
		width: 100%;
		height: 20vw;

		display: flex;
		flex-direction: column;
		justify-content: center;
		align-items: center;
	}

	.wrapper .business-info h1 {
		font-size: 5vw;
	}

	.wrapper .business-info p {
		font-size: 3vw;
		color: #666;
		margin-top: 1vw;
	}

	/****************** 食品列表部分 ******************/
	.wrapper .food {
		width: 100%;
		/*使用下外边距避开footer部分*/
		margin-bottom: 14vw;
	}

	.wrapper .food li {
		width: 100%;
		box-sizing: border-box;
		padding: 2.5vw;
		user-select: none;

		display: flex;
		justify-content: space-between;
		align-items: center;
	}

	.wrapper .food li .food-left {
		display: flex;
		align-items: center;
	}

	.wrapper .food li .food-left img {
		width: 20vw;
		height: 20vw;
	}

	.wrapper .food li .food-left .food-left-info {
		margin-left: 3vw;
	}

	.wrapper .food li .food-left .food-left-info h3 {
		font-size: 3.8vw;
		color: #555;
	}

	.wrapper .food li .food-left .food-left-info p {
		font-size: 3vw;
		color: #888;
		margin-top: 2vw;
	}

	.wrapper .food li .food-right {
		width: 16vw;
		display: flex;
		justify-content: space-between;
		align-items: center;
	}

	.wrapper .food li .food-right .fa-minus-circle {
		font-size: 5.5vw;
		color: #999;
		cursor: pointer;
	}

	.wrapper .food li .food-right p {
		font-size: 3.6vw;
		color: #333;
	}

	.wrapper .food li .food-right .fa-plus-circle {
		font-size: 5.5vw;
		color: #0097EF;
		cursor: pointer;
	}

	/****************** 购物车部分 ******************/
	.wrapper .cart {
		width: 100%;

		position: fixed;
		left: 0;
		bottom: 0;

		display: flex;
		flex-direction: column;
	}

	.wrapper .cart .cart-detailed {
		width: 100%;

		left: 0;
		bottom: 0;

		display: flex;
		flex-direction: column;
		justify-content: space-between;
		font-size: 4vw;

		padding: 0 0 5vw 0;
		/*background-color: #3190E8;*/
		background-color: #477DAE;
		color: #fff;
	}

	.wrapper .cart .cart-detailed li {
		left: 0;
		bottom: 0;

		display: flex;
		justify-content: space-between;
		padding: 0 2.5vw 0 2.5vw;
		margin: 2vw 0;
	}

	.wrapper .cart .cart-bottom {
		width: 100%;
		height: 14vw;

		left: 0;
		bottom: 0;

		display: flex;
	}

	.wrapper .cart .cart-bottom .cart-left {
		flex: 2;
		background-color: #505051;
		display: flex;
	}

	.wrapper .cart .cart-bottom .cart-left .cart-left-icon {
		width: 16vw;
		height: 16vw;
		box-sizing: border-box;
		border: solid 1.6vw #444;
		border-radius: 8vw;
		background-color: #3190E8;
		font-size: 7vw;
		color: #fff;

		display: flex;
		justify-content: center;
		align-items: center;

		margin-top: -4vw;
		margin-left: 3vw;

		position: relative;
	}

	.wrapper .cart .cart-bottom .cart-left .cart-left-icon-quantity {
		width: 5vw;
		height: 5vw;
		border-radius: 2.5vw;
		background-color: red;
		color: #fff;
		font-size: 3.6vw;

		display: flex;
		justify-content: center;
		align-items: center;

		position: absolute;
		right: -1.5vw;
		top: -1.5vw;
	}

	.wrapper .cart .cart-bottom .cart-left .cart-left-info p:first-child {
		font-size: 4.5vw;
		color: #fff;
		margin-top: 1vw;
	}

	.wrapper .cart .cart-bottom .cart-left .cart-left-info p:last-child {
		font-size: 2.8vw;
		color: #AAA;
	}

	.wrapper .cart .cart-bottom .cart-right {
		flex: 1;
	}

	/*达到起送费时的样式*/
	.wrapper .cart .cart-bottom .cart-right .cart-right-item {
		width: 100%;
		height: 100%;
		background-color: #38CA73;
		color: #fff;
		font-size: 4.5vw;
		font-weight: 700;
		user-select: none;
		cursor: pointer;

		display: flex;
		justify-content: center;
		align-items: center;
	}


	/*不够起送费时的样式（只有背景色和鼠标样式的区别）*/
	/*
	.wrapper .cart .cart-right .cart-right-item{
		width: 100%;
		height: 100%;
		background-color: #535356;
		color: #fff;
		font-size: 4.5vw;
		font-weight: 700;
		user-select: none;
		
		display: flex;
		justify-content: center;
		align-items: center;
	}
	*/
</style>
